I'm a bit confused about the practice of thinning radishes. I get that they need space to grow, but why not just plant them with adequate spacing from the start? I mean, if you have extra seeds, I see the logic in planting them all and then keeping the biggest ones, but does it really help them grow better if they're competing with each other? I'm starting to get the vibe that this is one of those quirky gardening habits that only seasoned folks seem to understand, and I'm not quite at that level yet.
4 Answers
Honestly, using double the seeds and then thinning them just seems like a lot of extra work for not much gain—like, maybe you end up with slightly larger radishes, but for a hobbyist, is it really worth it?
And let’s not forget, radish sprouts are delicious! They offer a mini harvest before the full-sized radishes are ready, which is always a nice bonus.
Not every seed will germinate, and for some plants, a lot might not sprout at all. By planting a few extra, you can remove the weaker ones instead of having to reseed if nothing comes up. Also, seedlings are super vulnerable to pests and diseases, so spreading them out is a good strategy.
It varies by seed type, but sometimes a significant percentage won't grow, so you overflow the area with seeds and thin them down. You could space them properly from the start, but you'd end up with patches of empty soil, especially if growing outside. In a controlled greenhouse, you'd have a way better chance of each seed sprouting and could be more careful about planting.

Yeah, some seeds are tiny, so it's a hassle to plant them one by one. It's just simpler to sow a bunch in one go and thin them out later.